1. Field of the Invention
The present invention relates to a body limb movement limiter that uses a non-Newtonian fluid so as to prevent sudden rapid movement of a person's arm or leg, or other joint, thereby preventing injury to the person's injury-recovering joint.
2. Background of the Prior Art
In recovering from an injury to the shoulder, knee, or other joint, with or without surgery to the joint, slow and gradual use of the affected area is desired in order to build strength and prevent shortening of the affected tendon or ligament. If the joint is subjected to sudden rapid forces the healing process to the affected area can be compromised resulting in a slowing of the healing of the affected area, reinjury, or further damage to the affected area which can result in the need for additional medical intervention. This not only results in further discomfort to the patient but slows the overall healing and recovery time.
Devices have been proposed that help limit movement of a person's joint such as the shoulder, knee, elbow, ankle, hip, etc., so as to prevent the patient from subjecting the joint to sudden rapid acceleration and consequent forces on the affected area. Such devices help prevent the attendant damage that can result from such rapid acceleration and work with varying degrees of efficiency.
The problem with the movement limiting devices found in the art is that such devices, being linear in their deceleration capacity, limit the normal and desired movements of a user of such devices. Such devices fail to discriminate between a desired normal movement associated with the joint and an undesired rapid movement than can cause damage to the user. These devices tend to make many normal movements, such as walking or carrying groceries relatively uncomfortable. While such discomforts may be an acceptable tradeoff to some, for the benefit of minimizing damage resulting from undesired rapid acceleration, these discomforts are less than ideal.
Other prior art devices will allow normal movement associated with a shoulder or a knee to a point and once that point is surpassed, a braking action is applied. While these devices will prevent much of the damage associated with full rapid acceleration of the affected area, the sudden braking action can cause a jerking force on the shoulder or knee, which can result in undue discomfort or some amount of damage to the tendons or ligaments thereat.
Therefore, there exists a need in the art for a device that will prevent rapid movement associated with a person's shoulder or knee or other joint. Such a device will allow the user to perform normal desirable functions without undue discomfort, yet will prevent sudden rapid acceleration of a person's limb, resulting in pain, reinjury or damage to the person's joint. The deceleration provided by such a device must be gradual so as not to exert a jerking force onto the user's affected area. Ideally, such a device must be of relatively simple design and construction and must be relatively easy to don and use.